Rules Don't Apply is a sloe gin Hollywood cocktail without fizz, Warren Beatty's made-up trip down memory lane. The movie revolves around Howard Hughes, but it's really about Beatty, set in Hollywood when he sowed his oats with a vaguely familiar leading man at certain angles.

Certainly there are less appealing vanity projects out there. Rules Don't Apply is affably mediocre, even tolerable between brief pleasures. The movie's lone constant amusement is Beatty's madcap portrayal of Hughes, keeping aloft his Spruce Goose of nonromantic not quite comedy.

After 15 years off screen, Beatty hasn't lost anything in magnetism. He's still a complex listener, eyes searching behind a squint, realizing then almost covering up what he thinks. Playing Hughes gives this signature acting tactic a workout, jumbled as his thoughts can be. Beatty is wonderful in a movie seldom rising to his level, except with Jeannine Oppewall's luscious old Hollywood production design.

Much of Rules Don't Apply's attention gets diverted to RKO contract player Marla Mabrey (Lily Collins), whose heartland purity earns the nickname "the virgin Marla." She's escorted by her prudish mother (Annette Bening) who knows Hughes' reputation with starlets. They await a meeting with Hughes to set up a screen test.

Marla's driver is Frank Forbes (Alden Ehrenreich), who also wants to meet Hughes to present a surefire real estate proposition. The tycoon has a strict no-dating policy for his employees, unless he's involved. Naturally, this rule will be skirted by Marla and Frank, with complications that won't be spoiled except its one fabrication too far.

"Never check an interesting fact," reads a title card, a quote attributed to Hughes, this movie's version of John Ford's print-the-legend code. Except the "facts" presented in Rules Don't Apply generally aren't interesting, refutable by anyone who saw The Aviator or The Hoax. Some are too inside Hollywood to notice but others are glaring for a movie set in 1964.

Beatty's screenplay jumbles decades and touchstones, making Jane Russell's bra in The Outlaw (1943) into a pressing topic and Clifford Irving's bogus 1972 Hughes biography into a key plot device. Hughes' famed Spruce Goose airboat (1947) figures in, as does his 1946 air crash in Beverly Hills. Too many chronology cheats to mention.

Each begs a question: With all this material, this high level of nostalgic design and Beatty's fascinating portrayal, why not just make a fanciful Howard Hughes biopic? The world and the man are big enough for two, and The Aviator didn't nail the later days that Beatty is perfect to play.

At times, Ehrenreich resembles Splendor in the Grass-era Beatty yet doesn't muster much beyond smoulder. There's a scene in which Hughes carefully directs his body double's hair styling, making the resemblance perfect. That's what Beatty does with Ehrenreich, playing a version of himself. Just as the real Beatty is guarded, not much is revealed about Frank.

Collins is an appealing presence, fine for Marla's ingenue rise but less so when dark clouds gather. She makes the character understandably desirable and believably chaste. Too much champagne leads to poor choices, both Marla's and Collins' clumsily acted drunk scene. Collins does possess a sweet singing voice on the title song but singing it three times is twice too many.

Easy to see why Beatty was smitten with Collins and with a reason to recreate a Hollywood culture long demolished then rebuilt shinier. Rules Don't Apply is a sincere valentine delivered insincerely, bypassing truth stranger than this tame fiction. As Ford would command: Just print the damn legend.